As computing power has continued to increase, the industry has started using virtualization technology to gain better utilization of hardware resources while allowing for isolated management on entire operating systems running on the same system. As companies have started migration of their Information Technology (IT) infrastructure onto virtual platforms, they have generally found the isolation of virtual machines to be beneficial, but have also found some drawbacks.
Many common problems such as backup and anti-virus could previously be solved by a single software component being installed on the physical server, often because they could provide their solution to the entire file system of the machine. With virtualization, however, each virtual machine manages its own isolated virtual resources, so these solutions have to be installed on each virtual machine, increasing management complexity and cost. Ideally, the virtual machine platform could provide some software with the ability to access resources across all virtual machines to provide common services while maintaining the majority of isolation.
With the specific resource in consideration here, the file system, this is difficult to achieve because virtual machine platforms usually provide storage to virtual machines in the form of virtual storage devices that mimic the way traditional storage devices work, leaving implementation of the file system abstraction to the file system drivers that run as part of the operating system kernel inside each virtual machine. As such, all known solutions fail to address current needs.